Is Seattle Tap Water Safe? What Seattle Public Utilities’s EPA Records Show
Seattle Public Utilities, which serves about 1,161,961 people in Washington, reported no PFAS above reporting limits in the EPA’s UCMR5 monitoring (2023-2025). Non-detect means not found above the EPA’s reporting floor in that round — not that the water was never tested again. Its most recent EPA-record lead 90th-percentile was 1.6 ppb — under the current 15 ppb action level. The system has 4 health-based violations on its federal SDWA record.
See the full interactive report for this system — every PFAS analyte, lead and copper rounds, violations, and the filter that handles what was found: open the Seattle report → Or check YOUR exact ZIP: check your water by ZIP →
Beyond PFAS: state-record results over an EPA limit
- tthm: 90.76 ug/L (highest sample 2015-08-04; 2012-2019 records, not current)
- haa5: 85.2 ug/L (highest sample 2017-05-02; 2012-2019 records, not current)
These are the highest samples in the state/EPA record for this system — a snapshot, not a current reading; the utility’s Consumer Confidence Report is the official current record.
Common questions about Seattle water
Is Seattle's tap water safe to drink?
Nothing in these records is above a current EPA limit, but there is something worth watching — a detection below the limit, an older exceedance, or a violation on record. See the card above. These are system-level records for public water systems, not a reading of any individual home’s tap, and they do not cover private wells. Confirm your own utility’s current Consumer Confidence Report, and test your tap if you’re unsure.
Does Seattle have PFAS in its drinking water?
Seattle Public Utilities reported no PFAS above reporting limits in UCMR5 monitoring.
Who supplies Seattle's drinking water?
Seattle Public Utilities (PWSID WA5377050) serves about 1,161,961 people, per EPA SDWIS records. A metro area is usually served by more than one water system — this page covers the area’s largest. Suburbs and neighboring towns often have their own systems with their own results; check your exact ZIP for yours.
How do I check my exact address?
Water systems report by system, not by address. Enter your ZIP on the water checker to see the system(s) serving it and what each reported.
Statewide, 8.4% of Washington’s UCMR5-tested systems reported PFOA or PFOS over the EPA limit — see the Washington water page.
Other large systems in Washington
See the 100 largest US water systems, water quality by state, and the national PFAS data study.
Sources: EPA UCMR5 occurrence data, Feb 2026 release (~95% complete; final reporting 2026) (2026-06); lead/copper + violations: EPA SDWIS via ECHO; population served: EPA SDWIS via ECHO (system-reported population served). PWSID WA5377050. Public-domain federal/state records; assembly by WaterByTheBook. Built 2026-07-25. Plain-markdown mirror: https://waterbythebook.com/md/seattle.md